In a process of fabricating a semiconductor, an etching process or plasma process such as a film-forming process is sometimes performed on a substrate such as a semiconductor wafer (hereinafter, referred to as a “wafer”) using capacitively-coupled plasma, inductively-coupled plasma or the like. A plasma processing apparatus using the capacitively-coupled plasma is configured such that a substrate is mounted on a mounting table including a lower electrode inside a processing container and a high frequency power is supplied between an upper electrode installed above the substrate and the lower electrode to plasmarize a process gas.
In recent years, there is a tendency of lowering a temperature in a plasma process. For example, low temperature plasma having a temperature of, e.g., 500 degrees C. or less, specifically, about 450 degrees C. or below, has been used. For example, when alumina (Al2O3) is used as a material of a mounting table, corrosion is prone to occur on a silicon oxide (SiO2) film. In addition, there is a need to reduce a resistance component in a high frequency circuit containing the plasma. In view of the foregoing, the use of a mounting table made of metal is under consideration.
On the other hand, in order to suppress the generation of particles or prevent the sliding of a wafer, a blasting process of spraying, for example, fine particles of alumina (Al2O3) onto a surface of a mounting table is performed to finish the mounting table to have a rough surface. However, if a plasma process is performed using the mounting table made of metal, which has been subjected to the blasting process, the plasma may become unstable, which fails to achieve a good plasma process.
For example, there is known a method of performing an alumina-based blasting process to enhance an adhesion of a thin film to a surface of a metal base material of a shower head part, and further performing another blasting process using a dry ice to remove the alumina particles which may remain after the blasting process. However, the related art does not describe on the association between a mounting table located at a back side of a substrate and stabilization of plasma.